Apparatus and method for induction motor heat transfer

Abstract

A heat sink apparatus for induction motors and other dynamoelectric machines. The heat sink has a mounting portion adapted for coupling to a motor housing. A first heat sink portion is adapted for insertion into a motor housing interior, such as through an aperture in the frame or bearing bracket, and is thermally coupled to a second heat sink portion that is adapted for orientation outside the housing. The heat sink apparatus first heat sink portion may be inserted within an air channel of a TEFC induction motor. The heat sink preferably has a higher heat transfer rate than the motor housing.

What is claimed is: 
     
       1. A dynamoelectric machine heat sink apparatus, comprising:
 a motor housing having a fan-end bearing bracket and an opposed drive-end bearing bracket through which a motor shaft that drives an external cooling fan extends; 
 a plurality of apertures through the fan-end bearing bracket and the drive-end bearing bracket; 
 a plurality of heat sinks, wherein each heat sink includes:
 a mounting portion adapted for coupling to the motor housing; 
 a first heat sink portion adapted for insertion into an interior of the motor housing through one of the apertures; and 
 a second heat sink portion thermally coupled to the first heat sink portion, adapted for orientation outside the motor housing, and including a plurality of parallel cooling fins, 
 the mounting portion comprising a mounting plate coupled to at least one of the heat sink portions, the mounting plate having a pair of opposed forks with tongues that are engaged by sliding insertion within peripheral grooves of the at least one of the heat sink portions, 
 wherein when the mounting portion is coupled to the motor housing, the heat sink is inserted through the aperture and covers the aperture, 
 
 wherein at least one first heat sink of the plurality of heat sinks is arranged through one of the apertures on the fan-end bearing bracket where the heat sink is in direct communication with airflow of the external cooling fan 
 wherein a plurality of second heat sinks of the plurality of heat sinks are arranged through apertures on the drive-end bearing bracket where the second heat sinks are in direct communication with the airflow of the external cooling fan, wherein the parallel cooling fins of the plurality of second heat sinks are orientated parallel to each other and extend outwardly from the drive-end bearing bracket in an axial direction. 
 
     
     
       2. The apparatus of  claim 1 , wherein the first heat sink portion of each heat sink has fins projecting away from the mounting plate. 
     
     
       3. The apparatus of  claim 1 , wherein the first and second heat sink portions comprising separate components respectively having coupled abutting faces. 
     
     
       4. The apparatus of  claim 3 , each of the first and second heat sink portions have fins projecting away from its respective face. 
     
     
       5. The apparatus of  claim 1 , wherein both heat sink portions have extruded fins projecting away from its respective face. 
     
     
       6. The apparatus of  claim 1 , wherein each heat sink has a higher heat transfer rate than that of the motor housing. 
     
     
       7. A dynamoelectric machine apparatus, comprising:
 a housing having an interior and an exterior surface,
 wherein the housing includes a fan-end bearing bracket and an opposed drive-end bearing bracket through which a motor shaft that drives an external cooling fan extends, and 
 a plurality of apertures through the fan-end bearing bracket and the drive-end bearing bracket; 
 
 a plurality of heat sinks, each heat sink having:
 a mounting portion coupled to the housing; 
 a first heat sink portion that is inserted into one of the apertures in communication with an interior of the housing; and 
 a second heat sink portion thermally coupled to the first heat sink portion, in communication with an environment outside the housing and including a plurality of parallel cooling fins, 
 wherein the mounting portion comprises a mounting plate coupled to at least one of the heat sink portions, the mounting plate having a pair of opposed forks with tongues that are engaged by sliding insertion within peripheral grooves of the at least one of the heat sink portions, and 
 
 wherein the plurality of apertures and heat sinks are oriented in arrays about the housing exterior surface, 
 wherein a plurality of first heat sinks of the plurality of heat sinks are arranged through apertures in a radial array on the fan-end bearing bracket where the plurality of first heat sinks are in direct communication with airflow of the external cooling fan, 
 wherein a plurality of second heat sinks of the plurality of heat sinks are arranged through apertures on the drive-end bearing bracket where the second heat sinks are in direct communication with the airflow of the external cooling fan, wherein the parallel cooling fins of the plurality of second heat sinks are orientated parallel to each other and extend outwardly from the drive-end bearing bracket in an axial direction. 
 
     
     
       8. The apparatus of  claim 7 , wherein the housing further comprises an internal airflow channel in communication with the first heat sink portion of each heat sink that extends through each aperture. 
     
     
       9. The apparatus of  claim 7 , wherein each heat sink has a higher heat transfer rate than that of the housing. 
     
     
       10. The apparatus of  claim 9 , wherein the first and second heat sink portions of each heat sink having fins. 
     
     
       11. The apparatus of  claim 9 , wherein each heat sink comprises material having higher thermal conductivity than material comprising the housing. 
     
     
       12. The apparatus of  claim 7 , wherein the first and second heat sink portions comprise separate components respectively having coupled abutting faces and fins projecting away from its face. 
     
     
       13. The apparatus of  claim 7 , wherein the housing includes a housing frame, where a plurality of third heat sinks of the plurality of heat sinks extend through apertures formed in the housing frame. 
     
     
       14. A method for cooling a dynamoelectric machine, comprising:
 providing a motor housing having an interior and an exterior of the housing;
 wherein the housing includes:
 a motor fan-end bearing bracket and an opposed drive-end bearing bracket through which a motor shaft that drives an external cooling fan extends; and 
 a plurality of apertures through the fan-end bearing bracket and the drive-end bearing bracket; 
 
 
 providing a plurality of heat sinks having a higher heat transfer rate than that of the housing, each heat sink comprising:
 a mounting portion coupled to the motor housing; 
 a first heat sink portion that is inserted into one of the apertures in communication with the housing interior; and 
 a second heat sink portion thermally coupled to the first heat sink portion, in communication with an environment outside the motor housing and including a plurality of parallel cooling fins; 
 wherein the mounting portion comprises a mounting plate coupled to at least one of the heat sink portions, the mounting plate having a pair of opposed forks with tongues that are engaged by sliding insertion within peripheral grooves of the at least one of the heat sink portions; and 
 
 inserting the plurality of heat sinks into the plurality of apertures so that the plurality of heat sinks is in thermal communication with the housing interior and exterior, 
 wherein the plurality of apertures and heat sinks are oriented in arrays about the housing exterior, 
 wherein a plurality of first heat sinks of the plurality of heat sinks are arranged through apertures in a radial array on the fan-end bearing bracket where the plurality of first heat sinks are in direct communication with airflow of the external cooling fan, 
 wherein a plurality of second heat sinks of the plurality of heat sinks are arranged through apertures on the drive-end bearing bracket where the second heat sinks are in direct communication with the airflow of the external cooling fan, wherein the parallel cooling fins of the plurality of second heat sinks are orientated parallel to each other and extend outwardly from the drive-end bearing bracket in an axial direction. 
 
     
     
       15. The method of  claim 14 , wherein the heat sinks are inserted into the apertures so that each is in thermal communication with an internal airflow channel defined within the housing interior.